#include <stdio.h>
int sum(int,int);
int product(int,int);
int difference(int,int);
int main(void){
  int a = 10;
  int b = 5;
  int result = 0;
  int (*pfun)(int,int);
  
  pfun=sum;
  result=pfun(a,b);
  printf("pfun = sum    result = %2d\n",result);
  
  pfun=product;
  result=pfun(a,b);
  printf("pfun = product    result = %2d\n",result);
  pfun=difference;
  result=pfun(a,b);
  printf("pfun = difference   result = %2d\n",result);
  
return 0;
}

int sum(int x,int y){
  return x+y;
}

int product(int x,int y){
  return x*y;
}

int difference(int x,int y){
  return x-y;
}
